This invention relates generally to actuating systems for aircraft wing leading edge slat and trailing edge flap panels and, particularly, to actuation systems of the type described whereby structural deflection of the airframe is inhibited from imposing unanticipated loads on either the actuating system components or on the airframe itself. More particularly, this invention relates to actuating systems including actuators for rotating the panels, wherein the actuators function as hinges for the panels as well as power units.
Various aircraft can benefit from an arrangement according to the present invention. For purposes of example, the leading edge wing slat system of the F-16 aircraft carries a long, full span slat panel powered by four actuators spaced along the wing length. The actuators also function as hinges for slat rotation. The actuators include gear arrangements, each having the same gear ratio, and input shafts connected via a torque tube to a hydraulic power unit. For a description of the F-16 leading edge slat system, reference is made to pages 155 and 157 of "The Great Book Of Modern War Planes", published by Portland House Publishing Company.
Historically, routine inspection of F-16 aircraft after exceeding two hundred hours of operational flying, has uncovered signs of excessive wear in the actuating mechanism controlling the position of the leading edge slat panel. Like problems continue to date with F-16 aircraft currently in service.
The present invention tends to alleviate this problem.
The applicants are aware of U.S. Pat. No. 4,470,366 (U.S. Class 114/280) which issued to Williams on Sep. 11, 1984; U.S. Pat. No. 3,140,066 (U.S. Class 244/42) which issued to Sutton on Jul. 7, 1964; and U.S. Pat. No. 1,813,485 (no class indicated) which issued to Cook on Jul. 7, 1931.
The Williams patent discloses a hinge for a hydrofoil wherein a foil is provided with an integral comb-like hinge member having hinge elements which are interfitted with hinge elements of a hinge block via a pin. The flap leading edge of the hydrofoil is fixedly secured to the hinge block at two span-wise inboard and outboard points defining "hard" pivotal connections wherein relative movement between the hinge block and flap is restrained. Intermediate the "hard" points, fore and aft relative sliding movement of the hinge block within the flap leading edge slot is permitted.
The Sutton patent discloses mounting means comprising hinge assemblies for supporting a flap on a wing of an aircraft. Two of the hinge assemblies are floating and are located intermediate the other two hinge assemblies which include a ball element associated with a hinge pin. A floating hinge is disposed between a pair of stable hinges. An intermediate link on the floating hinge permits fore and aft movement of a pivotal axis when the flap and wing are in the deflected state.
The Cook patent teaches a control mechanism for aircraft wherein a differential mechanism transmits motion to shafts in order to change the camber and angle of incidence of an air foil.
In regard to the Sutton patent, reference is made to U.S. Pat. No. 4,305,177 (U.S. Class 16/162) which issued to Feifel on Dec. 15, 1981, wherein a hinge pin is disclosed. With reference to the Cook patent, reference is made to U.S. Pat. No. 2,696,954 (U.S. Class 244/42) which issued to Harmen, et al on Dec. 14, 1954.
None of the aforementioned patents appear to teach, either singly or in combination, the structural arrangement herein disclosed.
The applicants are also aware of U.S. Pat. No. 4,248,105 (U.S. Class 74/710.5) which issued to Downing, et al on Feb. 3, 1981; U.S. Pat. No. 4,159,089 (U.S. Class 244/214) which issued to Cole on June 26, 1979; and U.S. Pat. No. 4,213,587 (U.S. Class 244/213) which issued to Roeseler, et al on Jul. 22, 1980. These patents are considered by the applicants to be of general interest only.